When we are healthy, our intestines are made up of a dynamic living ecosystem rich in microorganisms, including intestinal bacteria . But not all of them have the same influence on our bodies! In fact, some are beneficial for our health, while others can be described as “bad bacteria.” What are the differences between these two types of bacteria? How do they coexist within our intestinal microbiota? Why is a balance within this ecosystem essential for good health? In this article, we reveal everything you need to know about intestinal bacteria and their impact on our bodies.
Good intestinal bacteria: our allies for optimal health
What are good gut bacteria?
A healthy and balanced intestinal microbiota , composed of a rich and diverse ecosystem of good intestinal bacteria, is essential for our good health. Among these good bacteria , also called “probiotic bacteria” , we find in particular Lactobacilli and Bifidobacteria , two subgenres of bacteria that have been extensively studied and whose benefits for the body are recognized. The presence of these probiotic bacteria in a balanced manner within our intestinal microbiota helps ensure the proper functioning of our body.
The benefits of good gut bacteria
1 - Improved digestion and absorption of nutrients
Beneficial gut bacteria are actively involved in the breakdown and digestion of the food we eat, especially dietary fiber. Fiber produces compounds called enzymes that break down food into components, making it easier for our bodies to absorb and utilize it. This improved absorption of vitamins, minerals, and other nutrients is crucial for our health.
2 - Production of molecules beneficial to health
The good bacteria in our gut are also capable of producing beneficial molecules like short-chain fatty acids (SCFAs). These compounds are essential for nourishing the cells of the intestinal wall, strengthening the intestinal barrier , and maintaining healthy intestinal function . Additionally, these molecules also help regulate the inflammatory state within our gut, which is crucial for preventing inflammatory diseases.
3 - Protection against pathogens
Our good gut bacteria play a significant role in protecting us against pathogens and infections . By occupying attachment sites in the intestine, they prevent harmful bacteria from attaching and proliferating. In addition, they are also capable of producing antimicrobial substances, which help to slow the growth of pathogens (harmful bacteria, microbes, viruses, parasites) within our intestines.
4 - Strengthening the immune system
Another role of these good bacteria is to support the immune system , as they are able to interact closely with it. Indeed, they stimulate the production of immune cells and strengthen the immune response . You can understand why a healthy and balanced gut microbiota is essential to strengthen your immune system and thus reduce the risk of infections, allergies, and diseases.
5 - Protection of the intestinal barrier
Our good gut bacteria form a protective layer on our intestinal wall, preventing harmful molecules from passing through it, entering our bloodstream, and thus spreading throughout our body. In this sense, a healthy intestinal wall is essential for preventing inflammation and adverse reactions.
6 - Production of essential vitamins
Beneficial intestinal bacteria contribute to the production of certain essential vitamins such as vitamin K and certain B vitamins. These vitamins are important for our health because they participate in various metabolic processes within our body.
As you can see, by maintaining a balance of these good intestinal bacteria and preserving their activity, we positively influence several aspects of our health, allowing our body to function properly. Taking care of our intestinal microbiota is therefore essential. Indeed, we will now see that an imbalance in this microbiota is responsible for many ailments.
Dangerous intestinal bacteria: the enemies of our balance
While good gut bacteria are essential for good health, it's important to keep in mind that there are also bacteria that can disrupt intestinal balance and negatively impact our overall well-being. These so-called "pathogenic" bacteria can cause various health problems and must therefore be addressed promptly. Examples of these potentially dangerous bacteria include Escherichia coli (E. coli), Shigella, and Salmonella.
When these pathogenic bacteria predominate in our gut microbiota due to a favorable environment, an imbalance forms , leading to disruption of normal intestinal function and weakening of the intestinal barrier . This situation then compromises our health and can have negative consequences on our general well-being. Ingestion of these bacteria can lead to significant symptoms such as diarrhea, vomiting, abdominal pain, bloating or even fever. In some cases, these infections can become more severe and require medical intervention.
To prevent this risk, it is therefore essential to understand how we can be contaminated by these dangerous intestinal bacteria. This contamination most often occurs orally by consuming foods that carry them, drinking contaminated water or putting contaminated hands to your mouth, but it can also occur during travel to countries or regions at risk where there is a high presence of pathogenic intestinal bacteria. An imbalance in the intestinal microbiota can also promote the proliferation of these potentially dangerous bacteria and be responsible for various diseases.
Intestinal bacteria and parasites: terms not to be confused
Very often, intestinal bacteria are confused with parasites. Although these two organisms can coexist within our digestive system, there are significant differences between them, both in terms of nature and impact on our health. Indeed, unlike intestinal bacteria which are naturally present in our intestines and most of the time beneficial for our health, parasites are living organisms that can only live and develop in the presence of a host . They can infect our body in various ways: through contact with an object, an animal or food, or after consuming raw or undercooked meat or fish. This contamination can be responsible for health problems (digestive problems, infections, diseases, etc.).
Understanding the imbalance of the intestinal microbiota
An intestinal microbiota becomes unbalanced when pathogenic bacteria thrive at the expense of bacteria that are beneficial to our health. But how do we know if our microbiota is unbalanced? What factors can lead to this imbalance, and what are the solutions for caring for our microbiota?
We can talk about an imbalance in the intestinal microbiota in three cases: a decrease in the number of good bacteria , an increase in the number of pathogenic bacteria or a decrease in the diversity of the species of bacteria present in our intestines. This modification of the composition of the intestinal microbiota can be more or less significant, and therefore lead to different signs from one individual to another.
Telltale signs of gut bacteria imbalance
Several symptoms can reveal an alteration in the composition of your intestinal microbiota. Indeed, this imbalance is mainly manifested by intestinal disorders such as bloating , flatulence, digestive pain or even a disruption of intestinal transit . These telltale signs can be perceived punctually, following or not a meal, or specifically after consuming certain foods.
However, the telltale signs of an unbalanced gut microbiota can also affect other systems besides the digestive system. Indeed, it can also influence our energy, given that the gut microbiota influences our body's immune response to an "aggression." Furthermore, studies have shown a relationship between the composition, optimal or not, of our gut microbiota and our stress . Indeed, it has been highlighted that an imbalance in our gut microbiota can influence our mood and make us more sensitive to stress. Be aware that these telltale signs of an imbalance in the gut microbiota are specific to each individual. You may therefore find yourself in the signs mentioned above as different signs. In any case, do not hesitate to surround yourself with health professionals to remedy this.
Factors that can disrupt intestinal balance
The balance within our gut microbiota is essential for good health and overall well-being. However, several factors can disrupt this delicate balance, promoting the growth of pathogenic bacteria and thus compromising the proper functioning of our digestive system.
1 - An unbalanced diet
Consuming processed foods high in saturated fats or refined sugars can promote the growth of harmful bacteria in our intestines. In addition, a low intake of fiber-rich foods (fruits, vegetables, seeds, etc.) can deprive good gut bacteria of nutrients essential for their growth, leading to an imbalance in the gut microbiota.
2 - A significant intake of antibiotics
These are powerful medications that can eliminate harmful bacteria, but they can also disrupt the balance of the microbiota by destroying good bacteria. Overuse or inappropriate use of antibiotics can cause an imbalance in the gut microbiota and make the gut vulnerable to infections.
3 - Chronic stress
It can alter bacterial composition, increase intestinal inflammation, and weaken the intestinal barrier. These changes can promote the proliferation of bad bacteria and compromise digestive health.
4 - Lack of physical exercise
A sedentary lifestyle can also affect the diversity of gut bacteria. Regular exercise promotes intestinal motility and reduces chronic inflammation, which promotes the growth of good bacteria.
5 - Taking medication and toxic substances
Certain medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs), oral contraceptives, and acid-lowering medications, can disrupt intestinal balance. Additionally, exposure to toxic substances, such as pesticides and chemicals found in certain foods and personal care products, can also harm the health of our microbiota.
